The present invention relates to filler neck caps, and particularly to a rotatable cap for closing the open mouth of a filler neck. More particularly, the present invention relates to a filler neck closure cap designed to indicate to the user the minimum acceptable closure torque to effect a sealed position in a filler neck.
Conventional caps for closing the filler neck of a vehicle fuel tank typically include a closure member carrying a seal for closing and sealing the mouth of the filler neck and a handle for turning the closure member to mount the closure member and seal in the filler neck. A typical filler neck cap includes a ring-shaped seal made of a resilient gasket material that is compressed between the cap and a filler neck receiving the cap to establish a sealed connection between the cap and the filler neck when the cap is mounted on the filler neck.
Frequent over-tightening of a filler neck fuel cap can crush or otherwise damage the O-ring gasket which provides the seal between the cap and the filler neck. A torque-control mechanism was developed to limit positively the amount of torque which could be applied by a user in the cap-advancing direction as the user rotates the cap on the filler neck to its fully seated filler neck-closing position thereon. Thus, a torque-control mechanism helps minimize wear and tear on the O-ring gasket and preserves the sealing capability of the gasket. See, for example, U.S. Pat. No. 4,913,303 to Harris, U.S. Pat. No. 4,083,209 to Sloan, Jr., and U.S. Pat. No. 5,110,003 to MacWilliams and International (PCT) Publication No. WO 00/20292 (published Apr. 13, 2000) to Harris, the disclosures of which are hereby incorporated by reference herein.
In recent applications, however, a more pervasive problem is cap under-tightening, that is, failure of users to tighten the cap to a properly torqued installed position on a filler neck. A filler neck cap in accordance with the present disclosure is made to address the under-tightening problem.
According to the present disclosure, a filler neck cap includes a handle, a closure adapted to close a filler neck, and a torque-limit signaler coupled to the handle and the closure. The torque-limit signaler is configured to provide an audible and/or tactile and/or other receivable signal to a user (as the user is rotating a cap in a cap-advancing direction to its installed position within a tank filler neck) so that the user will be made aware that the cap has been xe2x80x9ctorquedxe2x80x9d or xe2x80x9ctightenedxe2x80x9d to an acceptable limit and has been installed properly within the filler neck. Once the user senses the signal produced by the torque-limit signaler, the user will know not to rotate the cap further in the cap-advancing direction and the cap therefore will be left in a properly torqued or tightened position within the filler neck.
In illustrative embodiments, the closure includes a closure base adapted to mate with the filler neck and a torque-transmission member positioned to lie between the handle and the closure base and rotate about the axis of rotation. The torque-limit signaler includes a driver coupled to the underside of the cap handle and a companion spring arm coupled to the torque-transmission member. The spring arm is arranged to maintain contact with the driver on the handle during an initial stage of cap installation in a filler neck so as to provide a torque-limited connection between the handle and the torque-transmission member during rotation of the handle about the axis of rotation in the cap-advancing direction.
Once sufficient torque has been applied to the handle about the axis of rotation and the closure base has been seated in the filler neck, the torque-limit signaler will function to provide a signal to a person rotating the handle about the axis of rotation in the cap-advancing direction that the cap has been torqued or tightened to an acceptable limit and the closure base has been installed properly within the filler neck. For example, as the person is rotating the handle in the cap-advancing direction, the driver (on the handle) will push the cantilevered spring arm (on the torque-transmission member) away to a driver-disengaged position to cause torque-transmission from the handle to the closure to be interrupted temporarily. As a result of this temporary interruption, the torque-transmission member and the closure base will not rotate about the axis of rotation in response to continued rotation of the handle in the cap-advancing direction through a small angle of about 15xc2x0.
An audible noise and/or a tactile sensation associated with such movement of the spring arm to a driver-disengaged positioned and provided to the person rotating the handle during the temporary interruption of torque-transmission from the handle to the closure will be the xe2x80x9csignalxe2x80x9d that the closure has been torqued or tightened sufficiently and that rotation of the handle in the cap-advancing direction is not causing the closure to rotate further in the filler neck. Once the person has rotated the handle in the cap-advancing direction through that small lost-motion angle relative to the torque-transmission member and the closure base, the driver on the handle will contact a fixed drive receiver located on the torque-transmission member while the spring arm is maintained on the driver-disengaged position to reestablish the driving (i.e. torque-transmitting) connection between the handle and closure in the filler neck.
Additional features of the invention will become apparent to those skilled in the art upon consideration of the following detailed description of preferred embodiments exemplifying the best mode of carrying out the invention as presently perceived.